放射治疗是肝癌的重要辅助治疗方法，尽管放射引起的肝病（RILD）的挑战限制了其实施。库普弗细胞 (KC) 是肝脏免疫系统的重要细胞群，其生物学功能可以通过多种表观遗传 RNA 修饰来调节，包括 N6-甲基腺苷 (m6A) 甲基化。然而，m6A 甲基化在 KC 诱导的 RILD 炎症反应中的机制仍不清楚。本研究探讨了 m6A 修饰在导致 RILD 的 KC 中的功能。采用甲基化 RNA 免疫沉淀测序 (MeRIP-seq) 和 RNA 转录组测序来探讨 3×8 Gy 照射后小鼠原代 KC 的 m6A 甲基化谱。 。使用蛋白质印迹和实时定量聚合酶链反应来评估基因表达。进行 DNA Pull-down 和 CHIP 测定来验证靶基因结合并识别结合位点。MeRIP-seq 显示照射后人 KC 中 m6A 修饰水平显着增加，表明上调的 m6A 在 RILD 中的潜在作用。此外，研究结果证实甲基转移酶样3（METTL3）作为主要调节剂促进TEAD1甲基化和基因表达，导致STING-NLRP3信号激活。重要的是，研究表明 IGF2BP2 作为 m6A“阅读器”发挥作用，识别甲基化 TEAD1 mRNA 并促进其稳定性。 METTL3/TEAD1 敲除消除了 STING-NLRP3 信号传导的激活，除了抑制炎症细胞因子和肝细胞凋亡外，还可以预防 RILD。此外，临床收集的照射后的人类正常肝组织样本显示，与未照射组相比，KC 中 STING 和 IL-1β 的表达增加。值得注意的是，STING 药理抑制减轻了小鼠辐射引起的肝损伤，表明其在 RILD 中的潜在治疗作用。我们的研究结果表明，TEAD1-STING-NLRP3 信号激活通过 METTL3 依赖的 m6A 修饰促进 RILD。版权所有 © 2023。由爱思唯尔公司出版

Radiation therapy is a vital adjuvant treatment for liver cancer, although the challenge of radiation-induced liver diseases (RILDs) limits its implementation. Kupffer cells (KCs) are a crucial cell population of the hepatic immune system and their biological function can be modulated by multiple epigenetic RNA modifications, including N6-methyladenosine (m6A) methylation. However, the mechanism for m6A methylation in KC-induced inflammatory response in RILD remains unclear. The present study investigated the function of m6A modification in KCs contributing to RILD.Methylated RNA-immunoprecipitation sequencing (MeRIP-seq) and RNA transcriptome sequencing were used to explore the m6A methylation profile of primary KCs isolated from mice after irradiation with 3 × 8 Gy. Western blotting and quantitative real-time polymerase chain reaction were used to evaluate gene expression. DNA pull-down and CHIP assays were performed to verify target gene binding and identify binding site.MeRIP-seq revealed a significantly increased m6A modification level in human KCs after irradiation, suggesting the potential role of upregulated m6A in RILD. In addition, the study results corroborated that methyltransferase-like 3 (METTL3) acts as a main modulator to promote the methylation and gene expression of TEAD1, leading to STING-NLRP3 signaling activation. Importantly, it was shown that IGF2BP2 functions as an m6A "reader" to recognize methylated TEAD1 mRNA and promote its stability. METTL3/TEAD1 knockdown abolished the activation of STING-NLRP3 signaling and protected against RILD in addition to suppressing inflammatory cytokines and hepatocyte apoptosis. Moreover, clinically collected human normal liver tissue samples post-irradiation showed increased expression of STING and IL-1β in KCs compared to the non-irradiation group. Notably, STING pharmacological inhibition alleviated irradiation-induced liver injury in mice, indicating its potential therapeutic role in RILD.The results of our study reveal that TEAD1-STING-NLRP3 signaling activation contributes to RILD via METTL3-dependent m6A modification.Copyright © 2023. Published by Elsevier Inc.